The predictive values of stoke volume variation and corrected flow time in fluid therapy responsiveness in neonatal septic shock

Abstract

Objective To study the predictive value of hemodynamic monitoring in the responsiveness of fluid therapy in neonatal septic shock. Method The 96 neonates with septic shock admitted to the NICU from Wuhan Children′s Hospital and Tongji Hospital between March 2014 to May 2017 were enrolled. Hemodynamics parameters of neonates pre-, 1 hour and 6 hour post-fluid therapy were supervised by ultrasonic cardiac output monitor. The hemodynamics parameters included cardiac index (CI), systemic vascular resistance (SVR), stroke volume (SV), stroke volume variation (SVV), stroke volume index(SVI) and corrected flow time (FTc). The SVI variation (△ SVI) were calculated based on the SVI among pre-and post-fluid therapy. According to the △SVI, these samples were assigned into two groups, responsive group with a △ SVI ≥10%, and the other was nonresponsive group respectively. T-test was applied to analyze the differences of hemodynamic parameters between two groups. The associations between SVV、FTc and △SVI were evaluated by bivariate correlation. Receiver operating characteristic curve (ROC) was used to evaluate the predictive value of SVV and FTc in fluid responsiveness. All statistical analyses were performed by SPSS 19.0, P<0.05 was considered as statistically significant. Result A total of 96 cases were enrolled, of which 54 were fluid responsive group, while 42 were nonresponsive group. (1) Before fluid resuscitation, the FTc in responsive and nonresponsive groups were (317.1±22.2) ms and (326.8±21.2) ms (P<0.05) respectively, SVV were (18.3±2.0)% and (15.0±2.6)% (P<0.05). SVV was significantly associated with △ SVI (r=0.542, P<0.05). (2) There were statistically significant differences in heart rate, mean arterial pressure, cardiac output, cardiac index, stroke volume and systemic vascular resistance index before treatment, 1 h and 6 h after treatment (P<0.05). (3) The area under the ROC of SVV (AUC) was 0.838 (95%CI 0.749~0.906). A sensitivity of 98.2%, and specificity 73.8% when SVV defined as 15.5%, with a significant difference when compared with FTc (AUC=0.642, 95%CI 0.538~0.737) (P<0.01). Conclusion SVV could be a reliable predictive index in estimating fluid responsiveness of neonatal septic shock and could be helpful parameter in clinic diagnosis. Key words: Shock, septic; Ultrasonography, doppler; Ultrasonic cardiac output monitor; Corrected flow time; Stroke volume variation